Well I have somewhat gone against my principles and planted some non native trees in my woodland. I have planted 24 Norway Spruce ie Christmas trees. However I will be removing them fairly quickly over the next 15 to 20 years.
Each year I pay around £30 for a Christmas tree. I do not like plastic trees and I also do not like the more popular Nordman trees. So its the traditional Norway Spruce for me, I know they do not retain their needles so well, but my thinking is that if I cut my selected tree down just before Christmas then it will be fresh and more likely to retain its needles for longer. When you buy one from the garden centre, you have no idea when it was cut, it could have been cut for easily a fortnight.
I bought my trees from Jackson nurseries, they cost me £21 and postage was a further £6.99. So for the cost of one small tree I now have 25.
I have planted them in one small area of the wood and they are about 3/4meters apart, I planted 24 of them and one I will plant in a large pot and that will be our Christmas tree for the next two years and after that I will commence cutting the ones in the wood. I would expect to cut more than one a year and provide free trees for family members and neighbours, which is a nice thing to do. That is if they want a Norway Spruce.
So I know I have made a fuss in the past about keeping non native trees out of our natural woodlands, but on balance I think this is OK.